Newbie question re: USB quality

If you have a properly set up USB dac and a reasonably well set up USB server, you are fine. I have tried many if not all mentioned options on this site. I do have a sotm td-USBexp out with battery power supply but the difference is minor at best. Concentrate on down stream. My view at this point is that speakers and their set up make the biggest difference. Vinyl still RULES but HD digital has never sounded been better.

On the wireless option, the Oppo does support DLNA, which is a wireless protocol for streaming music. Your player needs to have the capability to stream to a DLNA device. I am a Windows guy, so cannot help much on DLNA with iTunes and I do not think Audivana supports DLNA. Also, I think DLNA on the Oppo only supports PCM and not DSD, although that should be confirmed.

The problems that people try to address regarding usb are jitter (timing errors), poorly formed waveforms and electrical noise from the PC. Async usb greatly helps with the timing issues, as Doogie pointed out. The timing and waveform issues are often addressed by the usb to s/pdif converters, although s/pdif has issues of its own. The wireless solution completely isolates the PC from the Oppo, so you do not have to worry about the electric issues. Some people are also concerned about RF noise effecting the usb input. The quality of the 5V signal on the usb is also an issue. I am not sure if the Oppo uses the usb 5V signal or not.

As Pkoegz says, most of these effects are second or third order once you get things set up correctly, unless you have a very highly resolving system which usually costs a lot.

HELLO!
What about AES/EBU I have found it far superior in my set up to any USB that I started with

Markus - AES/EBU is essentially a professional version of S/PDIF. It uses balanced cabling and XRL connectors. The OP has a Macbook Air and an Oppo. How can he use AES/EBU?

In line with comments above, USB is not likely to be an issue for sound quality in the OPs particular case..